1.
while at it, taking the opportunity
Doing something additional while already engaged in another activity, taking advantage of the opportunity.
ついでに買ってきて。
Pick it up while you're at it.
ついでに expresses doing something additional while already engaged in another activity — taking advantage of an existing opportunity rather than making a separate effort.
Writing
Sometimes written as 序でに, though hiragana is far more common.
Common patterns
- 〜のついでに: while doing 〜
- 〜するついでに: while doing 〜
- ついでだから: since we're at it
- ついでに + request: while you're at it, please 〜
Usage
The secondary action should be something convenient or minor — not the main purpose. Saying ついでに implies the action is easy because you're already doing something related. It can sound rude if used for something that should be treated as important.
Register
Neutral — common in both casual conversation and polite speech.