Widely used way to study construction (7)
I believe the answer is:
reading
'construction' is the definition.
(thesaurus)
'widely used way to study' is the wordplay.
'widely used way' becomes 'ing' (I can't justify this - if you can you should give a lot more credence to this answer).
'to' says to put letters next to each other (I've seen this in other clues).
'study' becomes 'read' (synonyms).
'ing' after 'read' is 'READING'.
Can you help me to learn more?
(Other definitions for reading that I've seen before include "university town" , "lesson" , "First contribution to educational foundation" , "somewhere just off the M-four?" , "Quiet activity" .)