"Oh dear!" (4)
'oh dear' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for alas that I've seen before include "Cry of regret" , "Expression of regret" , "Regretfully!" , "Sad to say!" , "Cry of grief" .)
(Other definitions for love that I've seen before include "affair? On the contrary" , "It's nothing in tennis" , "Zero score, dear" , "Passionate desire" , "No points" .)
'oh dear' is the definition.
(both are said in recognition of a mistake)
This is all the clue.
(Other definitions for oops that I've seen before include "My bad" , "Exclamation recognising a mistake has been made" , "Something's been spilt!" , "I've messed up" , "Exclamation on making minor error" .)