An officer gets to see us sharpen up (5)
I believe the answer is:
focus
'sharpen up' is the definition.
'focus' can be an answer for 'sharpen' (focusing is a kind of sharpening). I am not sure about the 'up' bit.
'an officer gets to see us' is the wordplay.
'an officer' becomes 'foc' (I can't explain this - if you can you should believe this answer much more).
'gets' says to put letters next to each other.
'to see us' becomes 'us' (synonyms).
'foc'+'us'='FOCUS'
Can you help me to learn more?
(Other definitions for focus that I've seen before include "Cynosure" , "Target" , "Point at which light rays converge or diverge" , "Adjust camera lenses - concentrate" , "Point of convergence of light, etc" .)