Is put a pronoun

No, the Word 'put' is a verb, a Word for an action: put, puts, putting, put.

Example: Mother put the baby in the crib.

A pronoun is a Word that takes the place of a noun in a sentence.

Example: Mother put the baby in the crib. Then shesat down to read. (the pronoun 'she' takes the place of the noun 'mother' in the second sentence)