The term 'longtime pal' can be described by two crossword solutions: 'CRONY' (5 letters) and 'oldacquaintance' (15 letters). A CRONY is someone who is a close friend or companion, often for a long period of time. An oldacquaintance is someone who has been known for a long time, but may not necessarily be a close friend. Therefore, a longtime pal is someone who has been a close friend for a long period of time, or someone who has been known for a long time.