¦ interrogative adverb
1. at what time.
how soon.
2. in what circumstances.
¦ related adverb at which time or in which situation.
¦ conjunction
1. at or during the time that.
at any time that; whenever.
2. after which; and just then.
3. in view of the fact that; considering that.
4. although; whereas.
Origin
OE hwanne, hwenne; of Gmc origin.