ラク 
お.ちる お.ち お.とす 
() fall () drop () come down
                      
おち (n) (1) slip, omission, (2) outcome, final result, the end, (3) (uk) punch line (of a joke)
おちこぼれ (n) (1) (sens) leftovers, odds and ends, pickings, (2) (sens) student who can't keep up in school, dunce
おちる (v1,vi) (1) to fall down, to drop, (2) to fail (e.g. exam), (3) to crash, to degenerate, to degrade, (4) to fade, to come out (e.g. a stain)
おちあう (v5u,vi) (1) to meet, to gather, to rendezvous, (2) to join (of roads, rivers, etc.), to flow together
おちこむ (v5m,vi) (1) to feel down (sad), (2) to be in a slump (e.g. business, economy), to be in an unfavourable condition, (3) to fall into (e.g. a hole)
おちついた (adj-f) quiet, calm, composed
おちつき (n) (1) calmness, composure, presence of mind, (2) stability, steadiness
おちつく (v5k) to calm down, to settle down, to be steady, to settle in, to take up one's residence, to harmonize with, to harmonise with, to match, to restore presence of mind
おちど (n) mistake, error
おちば (n,vs,adj-no) fallen leaves, leaf litter, defoliation, shedding leaves
おとしあな (n) pitfall, trap, pit
おとしもの (n) lost property
おとす (v5s,vt) (1) to drop, to lose, to let fall, to shed (light), to cast (one's gaze), to pour in (liquid), to leave behind, (2) to clean off (dirt, makeup, paint, etc.), to remove (e.g. stains or facial hair), to lose, to spend money at a certain place, to omit, to leave out, to secretly let escape, (3) to lose (a match), to reject (an applicant), to fail (a course), to defeat (in an election), (4) to lower (e.g. shoulders or voice), to lessen (e.g. production or body weight), to worsen (quality), to reduce (e.g. rank or popularity), to speak badly of, to make light of, to fall into straitened circumstances, (5) to fall into (e.g. a dilemma or sin), to make one's own, to have one's bid accepted, to force surrender, to take (e.g. an enemy camp or castle), to forcefully convince, to press for a confession, to deal with, (6) (comp) to download, to copy from a computer to another medium, (7) (MA) to make someone swoon (judo), (8) to finish a story (e.g. with the punch line), (9) to finish (a period, e.g. of fasting)
らっか (n,vs) fall, drop, come down
らくご (n) rakugo story, (telling) a comic story
らくごか (n) rakugo story teller, comic story teller
らくさ (n) a head (of water), a difference
らくさつ (n,vs) having one's bid accepted (e.g. for contract), bid award, winning a tender
らくがき (n,vs) scrawl, scribble, graffiti
らくせん (n,vs) election loss, rejection
らくだい (n,vs) failure, dropping out of a class
らくたん (n,vs) discouragement, despondency, dejection
らくらい (n,vs) thunderbolt, bolt of lightning

Links: KanjiDic: EDict : Wikimedia
Etymologies: 中文字譜 : 説文解字