Plenty is a synonym for lots of. It begins with p.
A word that means friends that begins with P is pals.
Pioneer is a synonym for explorer. It begins with the letter p.
profit, progress, prosperity
Pester is a six letter word that means to annoy
proselyte
Pessimistic is a synonym for something bad happening. It begins with p.
Progress is a synonym for improve. It begins with the letter P.
Posey [or Posie or Posy] is a word that begins with the letter 'p' and means 'small bunch of flowers'. But these three different spellings of the same word aren't the only terms that have that meaning. Others include 'bouquet', 'nosegay', and 'tussie-mussie'.
atop
perfect
predict
pizzazz.