The term 'hapless one' can be described by three crossword solutions: SCHMO (5 letters), LOSER (5 letters), and GONER (5 letters). All three words are slang terms used to describe someone who is unfortunate, helpless, or doomed. SCHMO is a Yiddish word meaning a foolish or inept person, while LOSER is an informal term for someone who has failed or been defeated in some way. GONER is a slang term for someone who is doomed or has no chance of success. Together, these three words provide a vivid description of someone who is hapless.