Grumpy old American's after container on fuel lorry (12)
I believe the answer is:
cantankerous
'grumpy' is the definition.
(I've seen this in another clue)
'old american's after container on fuel lorry' is the wordplay.
I cannot quite understand how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is located in the answer.
'container' could be 'tank' (tank is a kind of container) and 'tank' is found within the answer.
'american' could be 'us' (abbreviation for United States) and 'us' is found in the answer.
The remaining letters 'caner' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for cantankerous that I've seen before include "Bloody-minded -- non-UK car seat (anag)" , "Awkward" , "Difficult" , "Stubbornly obstructive" , "Irritable" .)