What does the cryptic crossword clue "Engineer on-site a lot, in a jam? (4-2-4)" mean?

The wordplay uses an anagram. anagram of ONSITEALOT ("on-site a lot,") [anagram: "jam?"] = NOSETOTAIL The answer is NOSE-TO-TAIL.

Engineer on-site a lot, in a jam? (4-2-4)

Times Cryptic #28718 | 24 Across | 2023-09-26 flower