Function of angle grinder's initially to break into new tenant (7)
I believe the answer is:
tangent
'function of angle' is the definition.
'tangent' can be an answer for 'function' (tangent is a kind of function). I am not sure about the 'of angle' bit.
'grinder's initially to break into new tenant' is the wordplay.
'initially' indicates taking the first letters.
'to break into' indicates putting letters inside (inserted letters break into the word).
'new' indicates anagramming the letters.
The initial letter of 'grinders' is 'g'.
'tenant' anagrammed gives 'tanent'.
'g' placed inside 'tanent' is 'TANGENT'.
Can you help me to learn more?
(Other definitions for tangent that I've seen before include "Line touching curve at one point" , "Straight line that touches but does not intersect a circle" , "Trig ratio" , "Straight line touching a circle" , "mathematician's line" .)