The only common usage of the standalone word ma in Tagalog is short for Mama.

Ma, anong oras na?
Mom, what time is it now?

Ma! Nasaan ang baon ko?
Mom! Where's my food to go?

Ma... Pagod ka ba? May kailangan kasi ako, eh.
Mom... Are you tired? I need something, you see.

There is an obscure definition for ma as a species of mollusk but it is not common.

The syllable ma is very common as the first syllable of Tagalog adjectives and verbs. It is even used in front of English nouns. 

ma-pride (full of pride)

malaki, maliit, mataas, mababa, maganda, maitim, maputi, matanda
big, small, high, low, beautiful, black, white, old

maisagawa, magawa, maipagawa
to put into action, to be able to do, to be able to have something done