受身形 => Passive voice N4
~やむをえず  => unavoidable, no other way to do something N2
Necessity, obligation
~V使役受身      => causative-passive form N4
Conjugate verbs
むりをする => to work too hard, to try too hard, to strain oneself N3
Description
むき => facing towards N3
Direction
[受「う」]け[身「み」] => Passive, be V-ed. N4
Causative, Passive, Volitional
むしろ => rather; instead N2
Compare
...はむりだ... => impossible N4
Description
込む => to be crowded N3
なくて済む/ないで済む => get by without doing ~ N2
[使「し」][役「えき」][受「う」]け[身「み」] => Imperative N4
Causative, Passive, Volitional
ずに済む => get by without doing ~ N2