Answer:

plu

Answer	Crossword Clue
PLU	Perfect beginning?
PLU	Opposite of singular (abbr.)
PLU	Perfect start?

PLU	Like birds and bees: Abbr.
PLU	Not sing.
PLU	Like "algae" or "termini": Abbr.
PLU	Like "mice" and "men": Abbr.
PLU	Like cats and dogs: Abbr.
PLU	Prefix with perfect
PLU	Opposite of sing.
PLU	Like "ifs" and "buts": Abbr.

PLU	Like mice and men: Abbr.
PLU	Super: Comb. form.
PLU	More than one: Abbr.
PLU	Grammatical number: Abbr.
PLU	Multiple: Abbr.
PLU	Grammar abbreviation.
PLU	Noun form: Abbr.
PLU	Like men and women: Abbr.

PLU	Phenomena or personae: Abbr.
PLU	Like arts and crafts: Abbr.
PLU	More than one: abbr.
PLU	Kind of perfect
PLU	Perfect start to a grammarian?
PLU	Sing. opposite