Easy to reach sister's house where pigeon regularly nests (10)
I believe the answer is:
convenient
'easy' is the definition.
(thesaurus)
'house where pigeon regularly nests' is the wordplay.
'house' becomes 'convent' (convent is a kind of house).
'where' indicates an anagram (I've seen this in other clues).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'nests' means one lot of letters goes inside another (nest' can mean to fit one object into another).
The alternating letters of 'pigeon' are 'ien'.
'ien' is an anagram of 'nie'.
'convent' enclosing 'nie' is 'CONVENIENT'.
'to reach sister's' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for convenient that I've seen before include "Involving little trouble" , "Appropriate" , "Suitable" , "Suited" , "Handy" .)