Lift small alien bug (5)

I believe the answer is:

upset

I'm a little stuck... Click here to teach me more about this clue!

'bug' is the definition.
(I've seen this before)

'lift small alien' is the wordplay.
'lift small' becomes 'ups' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'alien' becomes 'et' (extra terrestrial).
'ups'+'et'='UPSET'

Can you help me to learn more?

(Other definitions for upset that I've seen before include "Disconcerted, discomposed" , "Overturn; unhappy" , "Caused grief" , "Disturb or knock over" , "Shock result!" .)

I've seen this clue in The Times.

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