We don't have synonyms for backbenchers yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are backbencher and backbenches.
(n) :
(politics) A Member of Parliament who does not have cabinet rank, and who therefore sits on one of the backbenches or in one of the back rows of the legislature.
(n) :
(education) A student who does not perform well, especially one who sits at the back of the classroom.
(n) :
(sports) A member of a team who does not usually play, but who is held in reserve.
(n) :
(by extension) Someone who does not play an active role in a process.
(n) :
(politics) A Member of Parliament who does not have cabinet rank, and who therefore sits on one of the backbenches or in one of the back rows of the legislature.
(n) :
(education) A student who does not perform well, especially one who sits at the back of the classroom.
(n) :
(sports) A member of a team who does not usually play, but who is held in reserve.
(n) :
(by extension) Someone who does not play an active role in a process.