人跟人之間那種熟
熟的對象從東西換成人：對方也「進到自己家門裡」了，於是說話、相處都放鬆下來。這正是字根 familia（同一個屋簷下的人）最早的那一層。
informal friendliness · noun · C1
a relaxed, friendly way of speaking to someone or behaving with them, as if you know them well.
親暱；隨和
核心畫面
Picture walking into your own kitchen in the dark and reaching straight for the light switch. You do not look for it — the hand already knows. familiarity is that state of having been around something long enough that it no longer needs working out: the subject, the street, the tool, or the person.
可以想成你摸黑走進自家廚房，手直接就伸向電燈開關——不用找，手自己記得。familiarity 就像這種狀態：一樣東…更多收起
可以想成你摸黑走進自家廚房，手直接就伸向電燈開關——不用找，手自己記得。familiarity 就像這種狀態：一樣東西你待得夠久了，久到它不再需要被弄懂。對象可以是一門學問、一條街、一個工具，也可以是一個人。From the word’s history
Familiarity goes back through Old French familiarite to Latin familiaritatem 'intimacy, close acquaintance', built on familia — which in Latin meant the household (the people under one roof), not blood relatives. So the oldest sense in English (c. 1200) was closeness between people; the modern 'I know this subject well' sense settled later, around 1600. The household picture is still what the word is doing: something has come inside your own four walls.
familiarity 經古法文 familiarite 上溯到拉丁文 familiaritatem（親近、熟識），字根 familia 在拉丁文裡指的是「同一個屋簷下的人」，而不是血緣上的家人。所以它在英文裡最早（約 1200 年）講的是人跟人之間的親近，「對某個題目很熟」這一層要到 1600 年前後才安定下來。那個「進到自己家門裡」的畫面，其實一直還在這個字裡運作。
Online Etymology Dictionary — https://www.etymonline.com/word/familiar
From the picture
Also in this word
knowledge from experience · noun · B2
a good knowledge of a subject, place, or tool that comes from study or contact.
熟悉；通曉
sense of familiarity · noun · B2
the feeling that something is well-known to you, often in a warm or comforting way.
熟悉感；親切感
原始詞典資料4 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。
familiaritynoun/fəmɪliˈæɹɪti/
- 1
The state of being extremely friendly; intimacy.
- It is also folly and injustice to deprive children[…]of their fathers familiaritie, and ever to shew them a surly, austere, grim, and disdainefull countenance, hoping thereby to keepe them in awfull feare and duteous obedience.
- Do not keep familiarity with any but those, with whom you may improve your time.
- 2
Undue intimacy; inappropriate informality, impertinence.
- Murrel did not in the least object to being called a monkey, yet he always felt a slight distaste when Julian Archer called him one.[…]It had to do with a fine shade between familiarity and intimacy which men like Murrel are never ready to disregard, however ready they may be to black their faces.
- 3
An instance of familiar behaviour.
- The gaunt men carried swords and daggers with a new familiarity, and even the women had poniards belted at their waists.
- 4
Close or habitual acquaintance with someone or something; understanding or recognition acquired from experience.
- The objects around have been seen so often, that they have at last become, as it were, unseen; their familiarity does not carry us out of ourselves, for all their associations are our own.
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。