To Amass
To Store, To Lay In Stock, To Have A Beard, To Grow A Beard
transitive verb, ichidan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means amass and the verb vocab version is to amass or to store.
This shares the same reading as 貯える, and the meanings are very close too!
彼はとても立派な口髭を蓄えています。
He’s growing such a splendid mustache.