also: でかけ
on the point of going out; about to leave
Used with に to indicate the moment just before departure. Often appears in phrases like 出掛けに.
See also: お出かけ
The phone rang just as I was about to leave.
just after leaving; while on the way
Also used with に to refer to the moment right after departure or during the early part of an outing. Less common than sense 1.
I realized I had forgotten something just after leaving.
It started raining just as I was about to leave.
It started raining just when I was on the point of going out.
I stopped by a convenience store on my way out.
I forgot my phone on my way out.
I'm in the middle of getting ready to go out.
外出 is a formal, neutral noun for 'going out (of the house)' used in writing and reports, whereas 出掛け specifically marks the instant right before or after departure.
出掛け refers to the exact moment of departure ('just as one is leaving'), whereas お出かけ more broadly means 'going out' or 'an outing' and is used in polite speech.
Standard kanji spelling; the reading でがけ is most common.
Alternate spelling with okurigana がけ instead of 掛け.
Irregular okurigana usage; reading でかけ is less common.
Compound of 出 (de, 'going out') + 掛け (kake, continuative form of 掛ける, 'to be about to'). Literally 'about to go out'.