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 anagramming the letters (I've seen this in other clues).
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'nests' indicates putting letters inside (nest' can mean to fit one object into another).
The alternating letters of 'pigeon' are 'ien'.
'ien' with letters rearranged gives 'nie'.
'convent' going around 'nie' is 'CONVENIENT'.
'to reach sister's' is the link.
I am not very happy about this link. Some or all of it may belong to 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" .)