【Forbearing】 , 【tolerant】 ,  【clement】 ,  【merciful】 ,  【lenient】 ,  【indulgent】  mean disinclined by nature, disposition, or circumstances to be severe or rigorous.

The same differences in implications and connotations are observable in their corresponding nouns forbearance, tolerance, clemency, mercifulness, leniency, indulgence and adverbs forbearingly, tolerantly, clemently, mercifully, leniently, indulgently.

【Forbearing】  , forbearance , and forbearingly imply patience under provocation and deliberate abstention from judging harshly, exacting punishment, or seeking vengeance or revenge.

【Tolerant】 , tolerance, and tolerantly imply both a freedom from bias or bigotry and a liberal attitude to opinions, especially to religious, philosophical, and political doctrines, other than one's own that keep one from severity or rigor in judging others who hold such opinions or doctrines or from wanting to impose restrictions upon their freedom to think as they will.

【Clement】 , clemency (see also MERCY ), and clemently suggest a temperament or nature that is mild and gentle, especially in judging offenders, and is slow to exact their punishment if a pardon or forgiveness will satisfy the purpose.

【Merciful】 , mercifulness, and mercifully imply both compassionate and 【forbearing】 treatment, especially of those who have offended or of those who merit severity or are defenseless against it.

【Lenient】  (see also SOFT ), leniency, and leniently differ from  【clement】 in suggesting usually softness rather than gentleness of temper, and a relaxation of discipline or rigor.

【Indulgent】 , indulgence, and indulgently usually imply compliancy as well as leniency; they imply, even more strongly than  【lenient】 , leniency, and leniently, concessions made out of charity or the exercise of clemency in the treatment of those who offend or who are under one's government or control.