Part
Medicare Part A covers inpatient care provided in hospitals or skilled nursing facilities, home health care services and hospice care for the terminally ill. Medicare Part A and Part B (Original Medicare) are managed by the federal government. Individuals who receive Social Security benefits are automatically enrolled in.
Component, ingredient, division, sector. Part, piece, portion, segment, section, fraction, fragment refer to something that is less than the whole.
Part is the general word: part of a house. A piece suggests a part which is itself a complete unit or it may mean an irregular fragment: a piece of pie; a piece of a broken vase. A portion is a part allotted or assigned to a person, purpose, etc.: a portion of food.
A segment is often a part into which something separates naturally: a segment of an orange. Section suggests a relatively substantial, clearly separate part that fits closely with other parts to form a whole: a section of a fishing rod, a book. Fraction suggests a less substantial but still clearly delimited part, often separate from other parts: a fraction of his former income. Fragment suggests a broken, inconsequential, incomplete part, with irregular or imprecise outlines or boundaries: a fragment of broken pottery, of information.
Part Number
Apportionment, lot. Sever, sunder, dissociate, disconnect, disjoin, detach. Mid-13c., 'division, portion of a whole,' from Old French part 'share, portion; character; power, dominion; side, way, path,' from Latin partem (nominative pars) 'a part, piece, a share, a division; a party or faction; a part of the body; a fraction; a function, office,' related to portio 'share, portion,' from PIE root.pere- 'to assign, allot' (cf. Greek peprotai 'it has been granted,' Sanskrit purtam 'reward,' Hittite parshiya- 'fraction, part').
It has replaced native (n.) in most senses. Theatrical sense (late 15c.) is from an actor's 'share' in a performance (The Latin plural partis was used in the same sense).
Meaning 'the parting of the hair' is 1890, American English. As an adjective from 1590s. Late Old English part 'part of speech' did not survive and the modern word is considered a separate borrowing. Phrase for the most part is from late 14c. To take part 'participate' is from late 14c.