Merriam-Webster Collegiate Dictionary - common

 I. adjective  Etymology: Middle English commun, from Anglo-French, from Latin communis — more at mean  Date: 13th century  1.  a. of or relating to a community at large ; public work for the ~ good  b. known to the community ~ nuisances  2.  a. belonging to or shared by two or more individuals or things or by all members of a group a ~ friend buried in a ~ grave  b. belonging equally to two or more mathematical entities triangles with a ~ base  c. having two or more branches ~ carotid artery  3.  a. occurring or appearing frequently ; familiar a ~ sight  b. of the best known or most frequently seen kind — used especially of plants and animals the ~ housefly  c. vernacular 2 ~ names  4.  a. widespread, general ~ knowledge  b. characterized by a lack of privilege or special status ~ people  c. just satisfying accustomed criteria ; elementary ~ decency  5.  a. falling below ordinary standards ; second-rate  b. lacking refinement ; coarse  6. denoting nominal relations by a single linguistic form that in a more highly inflected language might be denoted by two or more different forms ~ gender ~ case  7. of, relating to, or being ~ stock  • ~ly adverb  • ~ness noun Synonyms:  ~, ordinary, plain, familiar, popular, vulgar mean generally met with and not in any way special, strange, or unusual. ~ implies usual everyday quality or frequency of occurrence a ~ error lacked ~ honesty and may additionally suggest inferiority or coarseness ~ manners. ordinary stresses conformance in quality or kind with the regular order of things an ordinary pleasant summer day a very ordinary sort of man. plain is likely to suggest homely simplicity plain hard-working people. familiar stresses the fact of being generally known and easily recognized a familiar melody. popular applies to what is accepted by or prevalent among people in general sometimes in contrast to upper classes or special groups a writer of popular romances. vulgar otherwise similar to popular is likely to carry derogatory connotations (as of inferiority or coarseness) souvenirs designed to appeal to the vulgar taste.  II. noun  Date: 14th century  1. plural the ~ people  2. plural but singular in construction a dining hall  3. plural but singular or plural in construction, often capitalized  a. the political group or estate comprising the ~ers  b. the parliamentary representatives of the ~ers  c. House of Commons  4. the legal right of taking a profit in another's land in ~ with the owner or others  5. a piece of land subject to ~ use: as  a. undivided land used especially for pasture  b. a public open area in a municipality  6.  a. a religious service suitable for any of various festivals  b. ordinary 2  7. ~ stock