leather as a colloquialism for "thrash" should not be used by persons accustomed to refined diction.
lease and hire are loosely used interchangeably. An agent says he has property to hire (= for hire) while the tenant says he leases it. Strictly, the former leases and the latter hires.
leave is used transitively and intransitively, but critics have objected to the latter use on the ground that the verb to leave is not expressive of any occupation—does not, in fact, of itself convey any complete idea. It is true that if you speak you can speak only that which can be spoken, whereas if you leave you may leave home or any one of a thousand things; but as home (business or domestic) may be regarded as the chief of a man's possessions, it has been fancifully treated as being the one all-important subject to which unqualified leaving applies. One certainly may say with propriety "He has just left"; "We leave tomorrow." Avoid such locutions as "Leave me alone"; "leave her see it," as illiterate. Use let instead of leave.
left, to get: A slang phrase for "to be left behind; be beaten or outdone." Avoid such a vulgarism as "Did you ever get left?"
legacy. Compare bequest.
lend. Compare loan.
lengthen, lengthy: The verb means to "make or to grow longer." Its participle lengthened no more