Standing close, showing suppressed resentment (7)

I believe the answer is:

uptight

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

'suppressed resentment' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs sometimes mean the same thing.

'standing close' is the wordplay.
'standing' becomes 'up'.
'close' becomes 'tight' (synonyms).
'up'+'tight'='UPTIGHT'

'showing' is the link.

Can you help me to learn more?

(Other definitions for uptight that I've seen before include "Nervously tense (colloq.)" , "Highly-strung" , "Tensely repressed" , "Neurotic" , "Nervous, tense, anxious" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app