pica vs em

pica and em both are nouns.

Word	Noun	Adjective	Verb	Adverb
pica	Yes	No	No	No
em	Yes	No	No	No

As nouns, pica and em are synonyms defined as:

Other synonyms of pica include pica em.

pica (noun)	em (noun)
a linear unit (1/6 inch) used in printing	a quad with a square body
an eating disorder, frequent in children, in which non-nutritional objects are eaten persistently	a linear unit (1/6 inch) used in printing