One tick working a little lower (8)

'one' is the definition.
Both the definition and answer are singular nouns.
Perhaps they are linked in a way I don't understand?

'tick working a little lower' is the wordplay.
'tick' becomes 'mo' (both can mean a very short amount of time).
'working' becomes 'on' (on can mean working or activated).
'little' means to remove the last letter (the word is not quite complete).
'lower' becomes 'calf' (I've seen this before).
'mo'+'on'+'a'='moona'
'moona' with its final letter taken off is 'moon'.
'moon'+'calf'='MOONCALF'

Can you help me to learn more?