permitting, letting, favoring, allowing, sympathetic, loving, kind, forgiving
Some synonyms for compassion would be: humane, lenient, merciful, pitiful and tender.
The antonym of lenient is strict.
The opposite could be strict (not lenient), or harsh (the reverse of lenient).
The judge's decision was lenient, she was only given a fine.
Lenient: adj.: To go easy on someone or something. To be patient, kind and gentle.
A lenient sentence gives some leeway to the defendant and is less harsh than wanted or expected.
How about convenient
stern
"The teacher was very lenient with our grades on the last test.""His father is very lenient when it comes to punishment"The judge was lenient when handing down a sentence of 5 years in jail to the prisoner for murder"He was very strict about his students being promptly on time, but given the snowstorm that had left the campus under two feet of snow, he was very lenient with the students who showed up ten or fifteen minutes late that day".The judge was lenient when handing down a sentence of 5 years in jail to the prisoner for murder
The noun form is lenience, the subjective noun for relaxation or compassion in applying discipline or punishment.
Lenient means easy going and merciful. Someone who is lenient is not strict and will let things slide without consequences.
lenient,liberal