armpit
From Longman Dictionary of Contemporary EnglishRelated topics: Humanarmpitarm‧pit /ˈɑːmˌpɪt $ ˈɑːrm-/ noun [countable] 1 HBHthe hollow place under your arm where it joins your body2 → the armpit of somethingExamples from the Corpusarmpit• But in a moment or two he released Glover and shoved his two hands inside his armpits.• They also disagree about whether the glands in the armpit should be removed, treated with radiotherapy, or left alone.• He suddenly seized her under the armpits and swung her round and round, until she was breathless.