字的主幹（詞幹）
把植物搬進文法裡：一個字也有一根「莖」——加上 -ing、-ed 之後仍然不變的那部分，其他的字尾就像葉子和花一樣從它身上長出來。
word stem · noun · C1
the main part of a word that stays the same when you add endings to it, for example 'play' in 'playing' and 'played'
詞幹
核心畫面
Picture the long thin part of a plant standing up from the soil, carrying the leaves and the flower at its top. It is slim, it holds something up, and everything above it grows out of it. That upright slender support is the picture the noun keeps re-using.
可以想成植物從土裡直挺挺長上來的那根細長的部分：葉子和花都掛在它身上。它很細、撐著東西，而且上面的一切都是從它長出去…更多收起
可以想成植物從土裡直挺挺長上來的那根細長的部分：葉子和花都掛在它身上。它很細、撐著東西，而且上面的一切都是從它長出去的。名詞的各種用法，看起來都是同一根細長支柱換了個場合出現。From the word’s history
Etymonline traces the noun stem to Proto-Germanic *stamniz, from the PIE root *sta- 'to stand, make or be firm' — the family that also gives English stand. The upright, standing-up support is there in the root itself.
根據 Etymonline，名詞 stem 可追到原始日耳曼語 *stamniz，再往上是印歐語根 *sta-「站立、使穩固」——英文的 stand 也出自同一家。所以「直立起來、撐住上面」這個感覺，在字根裡就已經在了。
Etymonline, https://www.etymonline.com/word/stem
From the picture
止住、擋下來（動詞）
這一族和上面那根植物的莖只是拼法相同，來源不一樣，不必硬把它想成從花莖延伸出來的意思；它自己的畫面比較像「把流出來的東西攔住、堵起來」。
stem bleeding · verb · C1
to stop a liquid, especially blood, from flowing
止（血、水）
Also in this word
plant stem · noun · B1
the long thin part of a plant that grows up from the ground, and from which leaves, flowers, or fruit grow
莖 / 梗
glass stem · noun · B2
The thin upright part that holds up the bowl of a glass or vase.
（杯、瓶的）細柄
pipe stem · noun · C1
the long narrow tube of a pipe used for smoking, which reaches from the bowl to your mouth
菸斗的管身
原始詞典資料34 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
Stemname
- 1
A surname.
stemnoun詞源 1/stɛm/
- 1
The stock of a family; a race or generation of progenitors.
- Where ye may all that are of noble ſtemm / Approach, and kiſs her ſacred veſtures hemm.
- While I do pray, learn here thy stem / And true descent.
- 2
A branch of a family.
- This is a stem / Of that victorious stock.
- 3
biologynatural-sciencestaxonomyA branch of a family.
- 4
An advanced or leading position; the lookout.
- Wolsey sat at the stem more than twenty years.
- 5
biologybotanynatural-sciencesThe above-ground stalk (technically axis) of a vascular plant, and certain anatomically similar, below-ground organs such as rhizomes, bulbs, tubers, and corms.
- After they are shot up thirty feet in length, they spread a very large top, having no bough nor twig in the trunk or the stem.
- He had placed her upon the grass by now, her back resting against the stem of a huge tree. At her question he stepped back where he could the better see her face.
- 6
A slender supporting member of an individual part of a plant such as a flower or a leaf; also, by analogy, the shaft of a feather.
- the stem of an apple or a cherry
- Earless ghost swift moths become “invisible” to echolocating bats by forming mating clusters close (less than half a meter) above vegetation and effectively blending into the clutter of echoes that the bat receives from the leaves and stems around them.
- 7
A narrow part on certain man-made objects, such as a wine glass, a tobacco pipe, a spoon.
- 8
human-scienceslinguisticssciencesThe main part of an uninflected word to which affixes may be added to form inflections of the word. A stem often has a more fundamental root. Systematic conjugations and declensions derive from their stems.
- The praenomen and nomen for the most part consisted of simple stems with the suffix -us or -ius, which correspond to some of the contracted forms in other languages […].
另外 11 個記錄的用法
- 9
slangA person's leg.
- She was perfectly, fuckably proportioned everywhere else, both above and below her waist. A pocket-size Venus, with the longest stems he'd ever seen on someone so dang diminutive.
- 10
slangThe penis.
- Waves of ecstasy roll through him as the moustachioed Casanova slides his stem in and out of the spaced-out chick.
- 11
mediapublishingtypographyA vertical stroke of a letter.
- 12
entertainmentlifestylemusicA vertical stroke marking the length of a note in written music.
- 13
entertainmentlifestylemusicA premixed portion of a track for use in audio mastering and remixing.
- Stem mastering processes a mix by breaking it down into several manageable pieces—that is, stereo stems. The stem approach allows the mastering engineer the opportunity to make larger or smaller changes to separate mix elements before the final compression and limiting are applied to the complete mix.
- 14
nauticaltransportThe vertical or nearly vertical forward extension of the keel, to which the forward ends of the planks or strakes are attached.
- 15
nauticaltransportThe front part of a vessel.
- from stem to stern
- Both we will walke vpon the loftie cliffes, And Chriſtian Merchants that with Ruſſian ſtems Plow vp huge furrowes in the Caſpian ſea, Shall vaile to vs, as Lords of al the Lake.
- 16
cyclinghobbieslifestyleA component on a bicycle that connects the handlebars to the bicycle fork.
- 17
anatomymedicinesciencesA part of an anatomic structure considered without its possible branches or ramifications.
- 18
slangA crack pipe; or the long, hollow portion of a similar pipe (i.e. meth pipe) resembling a crack pipe.
- 19
A winder on a clock, watch, or similar mechanism.
stemverb詞源 1/stɛm/
- 1
To remove the stem from.
- to stem cherries; to stem tobacco leaves
- 2
To be caused or derived; to originate.
- The current crisis stems from the short-sighted politics of the previous government.
- Weight stigma often stems from an idea that patients are at fault for their body size.
- 3
To descend in a family line.
- 4
To direct the stem (of a ship) against; to make headway against.
- Nor is the pre-eminent tremendousness of the great Sperm Whale anywhere more feelingly comprehended, than on board of those prows which stem him.
- 5
obsoleteTo hit with the stem of a ship; to ram.
- As when two warlike Brigandines at sea, / With murdrous weapons arm'd to cruell fight, / Doe meete together on the watry lea, / They stemme ech other with so fell despight, / That with the shocke of their owne heedlesse might, / Their wooden ribs are shaken nigh a sonder […]
- 6
To ram (clay, etc.) into a blasting hole.
stemverb詞源 2/stɛm/
- 1
To stop, hinder (for instance, a river or blood).
- to stem a tide
- [They] stem the flood with their erected breasts.
- 2
hobbieslifestyleskiingTo move the feet apart and point the tips of the skis inward in order to slow down the speed or to facilitate a turn.
- 3
climbinghobbieslifestyleTo use a stance with the feet spread apart, bracing them in opposite directions against the two walls of a chimney or dihedral.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。