[使「し」][役「えき」] => Coercive, permission, allow, make N4
Causative, Passive, Volitional
[使「し」][役「えき」][受「う」]け[身「み」] => Imperative N4
Causative, Passive, Volitional
ざるを[得「え」]ない => Only A is left to do/can be done N2
(Not)only, (Not) even
を[禁「きん」]じ[得「え」]ない => Can't help but do A, can't hold back from A (emotional response to something) N1
Will, Decision, Doing