Eats tuna salad, drinks lots of tea and gets thinner (10)

'gets thinner' is the definition.
I can't tell whether this defines the answer.

'eats tuna salad drinks lots of tea' is the wordplay.
'salad' indicates an anagram (salad can refer to a mixture).
'drinks' means one lot of letters goes inside another.
'lots of' means to remove the last letter (the majority of the word).
'eats'+'tuna'='eatstuna'
'eatstuna' anagrammed gives 'attenuas'.
'tea' with its final letter taken off is 'te'.
'attenuas' placed around 'te' is 'ATTENUATES'.

'and' acts as a link.

Can you help me to learn more?