What is the meaning of If?

Supposing that, assuming that, in the circumstances that; used to introduce a condition or choice.

In the event that a statement is true (a programming statement that acts in a similar manner).

Supposing that; used with past or past perfect subjunctive indicating that the condition is closed.

Supposing that; given that; supposing it is the case that.

Although; used to introduce a concession.

Whether; used to introduce a noun clause, an indirect question, that functions as the direct object of certain verbs.

Even if; even in the circumstances that.

Introducing a relevance conditional.

An uncertainty, possibility, condition, doubt etc.

yew

"what-if" alternative history / events

if, on condition that

yew

yew wood

Alternative form of yith

yew

if

Source: wiktionary.org