To be in debate; to engage in discussion; to dispute; to argue.
To be in opposition; to contest; to dispute; to vie; to quarrel; to fight.
To believe (something is reasonable) and argue (for it); to advocate.
To struggle or exert oneself to obtain or retain possession of, or to defend.
contend with: To try to cope with a difficulty or problem.
To intervene in a dispute, or in a conversation.
To interrupt a conversation by introducing a different subject or making a comment.
To insert something (or oneself) between other things.
To be inserted between parts or things; to come between.
To offer (one's help or services).