thumb · noun C /θʌm/
thumb
B1 the short thick finger on the side of your hand which makes it possible to hold and pick things up easily
Dictionary example:
She still sucks her thumb.
Learner example:
After, we lit the candles, took our seats round the table, put all [our] hands in front of us above the table and joined thumbs and little fingers to make a circle. (First Certificate in English; B2; Polish)
a rule of thumb
C1 a way of judging something that is not exact but which will help you to be correct enough
Dictionary example:
As a rule of thumb, you need one egg for every 125g flour.
Learner example:
I think that I'm only one among many that have a diary a[s] their most precious possession, but, as a rule of thumb, I would think that people value objects in terms of how replace[a]ble they are. (Certificate of Proficiency in English; C2; Italian)
