big yawn
A large, noticeable yawn, often implying boredom or sleepiness.
I let out a big yawn during the meeting.
彼は大あくびをしながら起きてきた。
He got up while giving a huge yawn.
Common mixed kanji-kana spelling.
Rare full-kanji spelling; 欠伸 is itself uncommon for あくび.
Compound of 大 (おお, 'big') and あくび ('yawn'). The reading おおあくび follows standard rendaku rules.