informal <非正式>
1
- used to express assent, especially to a superior尤用于表示对上级的赞同是的, 先生：
'Do you understand me?' 'Yessir!'
“你明白我的意思吗？”“是的, 先生。”
1.1
- N. Amer. used to express emphatic affirmation〈北美〉［用于表示强势的肯定］是的, 真的：
yessir the food was cheap.
食品真的便宜。
with obj.
- defer to (someone) as a superior, or indicate agreement to (someone)服从上级; 同意：
you're used to people yessirring you left and right.
你已习惯人们对你惟命是从。
词源
early 20th cent.: alteration of yes sir.