ace
PRO
Dan
Dan
Mogul.
One seven letter word, One two letter word and a five letter word, One three letter word and a four letter word, One three letter word and two two letter words, Two three letter words, Three two letter words, A two letter word and a four letter word, A six letter word, A two letter word and a three letter word, A five letter word, Two two letter words, A four letter word, A three letter word, or A two letter word.
professional
the words for food expert are gourmet, epicure, gastronome.
Authority can be used as another word for expert and starts with an "A". Example: An authority on the subject of crime, notes that...
I've is a three letter word. I'll is another three letter word.
Imp is a three-letter word for rapscallion.
A three letter word for help is aid.