As an expert in the field related to the crossword clue ‘Goofing off‘, I can confirm that the answer to this clue is ‘MONKEYINGAROUND‘.
‘Monkeying around‘ is a common idiomatic expression that means behaving like a playful and mischievous monkey. The phrase is often used to describe someone who is not doing what they should be doing and instead wasting time by playing, joking or fooling around.
This phrase is based on the playful nature and entertaining behavior of monkeys in the wild. So when someone is said to be “monkeying around,” it implies that they are behaving in a similarly playful and entertaining manner.
Overall, when you come across the crossword clue ‘Goofing off‘, you can confidently fill in ‘MONKEYINGAROUND‘ knowing that it perfectly captures the essence of someone wasting time and behaving in a playful and mischievous manner just like a monkey.