Union station? (6)
'union station?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for altar that I've seen before include "Focus of church worship" , "Table used for religious ceremony" , "Where Lucy Ashton was led" , "place of unions" , "Holy table" .)
(Other definitions for chapel that I've seen before include "Might he clap in the place of worship?" , "house of prayer" , "Private church" , "Part of or alternative to church" , "Local printers" .)