In order to cure, remove or counteract.

• I need to spray my house for termites.
• The doctor treated me for arthritis.

So as to allow (something or someone) to take position.

• Make way for the president!
• Clear the shelves for our new Christmas stock!

In anticipation of.

• Stand by for your cue.
• Prepare for battle.

As an evaluation of; as to evaluate in connection with.

• I am grading for style on this paper.
• History will judge you for your actions.

So as to identify or locate.

• They swept the area for enemy operatives.
• Police combed his flat for clues.

Over (a period of time).

• I've lived here for three years.
• They fought for days over a silly pencil.

Throughout or across (a distance in space).

• I can see for miles.
• For many miles about / There's scarce a bush.

Used to introduce a subject of a to-infinitive clause.

• It seems unreasonable for our boss to withhold our wages.
• I don't think it's a good idea for you and me to meet.

On behalf of.

• I will stand in for him.
• I speak for the Prime Minister.

In the role or capacity of; instead of; in place of.

• I used a hay bale for a bed.
• He's got a turnip for a brain.

In exchange for; in correspondence or equivalence with.

• I got five hundred pounds for that old car!
• He matched me blow for blow.

In order to obtain or acquire.

• I am aiming for completion by the end of business Thursday.
• He's going for his doctorate.

By the standards of, usually with the implication that those standards are lower than one might otherwise expect; considering as an example of a role or of limitations.

• Fair for its day.
• She's spry for an old lady.

To be, or as being.

• Don't take me for a fool.
• 17th century Abraham Cowley, Of Wit We take a falling meteor for a star.

Despite, in spite of.

• For all his expensive education, he didn't seem very bright.
• "You must keep your head. There is still hope." "Hope!" "Yes; plentiful hope -- for all this destruction!"

Indicating something desired or anticipated.

• O for the wings of a dove.
• Ah! for wings to soar …

Introducing the first item(s) in a potential sequence .

• Go scuba diving? For one thing, I can't even swim.
• For another, we don't have any equipment.

In honor of; after.

• He is named for his grandfather.

Due for or facing (a certain outcome or fate).

• He totally screwed up that project. Now he's surely for the sack.

Out of; used to indicate a fraction, a ratio

• In term of base hits, Jones was three for four on the day

businesscommerceFor the price of.

• Special offer: three for two.

ball-gamescricketgamesUsed as part of a score to indicate the number of wickets that have fallen.

• At close of play, England were 305 for 3.

obsoleteIndicating that in prevention of which, or through fear of which, anything is done.

• We'll have a bib, for spoiling of thy doublet.

So (that), in order to.

• He took the swing shift for he could get more overtime.

Used in various other more-or-less idiomatic ways to construe individual verbs, indicating various semantic relationships such as target, purpose, result, etc.; see also the entries for individual phrasal verbs, e.g. ask for, look for, stand for, etc.

• to account for one's whereabouts    to care for a relative    to settle for second best    to allow for mistakes

human-scienceslogicmathematicsUsed to introduce a variable subject to quantification, or to establish a restricting domain for a subsequent mathematical statement.

• The identity f(x+y) = f(x) + f(y) holds for all x,y ∈ G.
• For each set A, there is a set B whose elements are exactly the subsets of A. For x > 0, the function ln(x) is strictly increasing.