腋下

腋下	yè xià	underarm / armpit
腋	yè	armpit / (biology) axilla / (botany) axil / Taiwan pr. [yi4]
下	xià	down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action