Be obvious to smirk about Mark getting dismissed by amateur (5,3,1,4)

'be obvious to smirk' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'mark getting dismissed by amateur' is the wordplay.
I cannot really see how this works, but
'mark' could be 'tick' (I've seen this before) and 'tick' is located in the answer.
'dismissed' could be 'out' (I've seen this before) and 'out' is found in the answer.
'amateur' could be 'am' (as in am-dram) and 'am' is found in the answer.
The remaining letters 'sile' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

'about' is the link.

Can you help me to learn more?