single-seater;  single-seated;  sitting alone
 simple;  easy;  uncomplicated;  brief;  quick;  light
 simple;  plain;  uncomplicated;  straightforward;  simple-minded;  naive
 (single-industry) industrial union
 simply;  merely;  only;  solely
 unit;  denomination;  credit (in school);  in units of (e.g. "in thousands");  in amounts of
 sole;  single;  solo;  independence;  singleness;  singularity
 simple substance (e.g. chemical);  something standing alone;  separate item;  solo item
 monotony;  monotone;  dullness;  monotone;  monotonic
 single horseman;  wait for one tile to finish one's pair and one's hand;  wait for half of one's pair with four melds completed
 single;  simple;  sole;  individual;  unitary
 single eye;  one eye;  single lens;  simple eye;  ocellus
 single cell;  simple-minded person;  one-track-minded person
 two-wheeled motor vehicle;  motorcycle;  motorbike
 single colour (color);  monochrome
 single track (railway);  single line;  solid wire;  solid-core wire;  single-strand wire
 single line (of ships);  single line formation;  line of battle
 monotypic (taxon);  monotype;  monomorphic;  single impression die
 single sound;  monosyllable;  phone;  monotone (harmonica, etc.)
 simple;  easy;  uncomplicated
 single-theater;  independent (cinema);  art-house (film)
 going alone;  doing by oneself
 isolation (e.g. of a particular chemical substance within a mixture)
 monocrystal;  single crystal
 simple system;  single-entry (bookkeeping)
 perfecta (bet);  exacta;  straight forecast
 single phase;  haploid phase
 monolayer;  single layer;  single story (storey)
 base hit;  one-base hit;  single
 infectious mononucleosis;  mono;  glandular fever
 single yarn (in spinning)
 third person singular present
 worker who only does one task;  single skill worker
 (being a) fan of a single member of a music group (esp. idol group)
 single authorship (of a book, paper, etc.);  single-author work
 single column (in marching)
 simple harmonic motion;  simple harmonic oscillation
 college (offering a single course of study)
 first or solo run in a race (grand prix, horse race, etc.)
 single standard;  monometallism;  monometalism
 single-kanji conversion (in an input method)
 single-entry (bookkeeping);  voting for one person only
 singles (tennis, badminton, etc.)
 Indian file;  single file;  single column
 monophthong;  simple vowel
 monostable trigger circuit
 monostable (trigger) circuit
 single-hit decision table
 synapsids;  theropsids;  mammal-like reptiles
 menu (at a Chinese restaurant)
 Synapsida (class of amniotes)
 layman's terms;  simple name;  uncomplicated term;  singular
 single-drug;  single-agent;  single-treatment
 single-answer question format
 single site approximation