Tiny mother got least (7)
I believe the answer is:
minimum
'least' is the definition.
(similar in meaning)
'tiny mother' is the wordplay.
'tiny' becomes 'mini'.
'mother' becomes 'mum' (informal term for mother).
'mini'+'mum'='MINIMUM'
'got' is the link.
(Other definitions for minimum that I've seen before include "Lowest point" , "Lower limit" , "The least of smallest amount possible" , "Smallest possible quantity" , "Nadir" .)