School bus many regularly filled, forming queue (6)
I believe the answer is:
column
'queue' is the definition.
(thesaurus)
'school bus many regularly filled' is the wordplay.
'regularly filled' means one should take alternating letters (letters taken at regular intervals).
'school'+'bus'+'many'='schoolbusmany'
The alternate letters of 'schoolbusmany' are 'COLUMN'.
'forming' is the link.
(Other definitions for column that I've seen before include "Nelson's supporter?" , "Vertical newspaper unit" , "Pillar or queue" , "supporting Nelson?" , "Tall cylindrical vertical upright" .)