specialize v.

c. 1200, "given or granted in unusual circumstances, exceptional;" also "specific" as opposed to general or common; from Old French special, especial "special, particular, unusual" (12c., Modern French spécial) and directly from Latin specialis "individual, particular" (source also of Spanish especial, Italian speziale), from species "appearance, kind, sort" (see species).

Meaning "marked off from others by some distinguishing quality; dear, favored" is recorded from c. 1300. Also from c. 1300 is the sense of "selected for an important task; specially chosen." From mid-14c. as "extraordinary, distinguished, having a distinctive character," on the notion of "used for special occasions;" hence "excellent; precious."

From late 14c. as "individual, particular; characteristic." The meaning "limited as to function, operation, or purpose" is from 14c., but developed especially in the 19c. Special effects first attested 1951. Special interest in U.S. political sense is from 1910. Special pleading is recorded by 1680s, a term that had a sound legal meaning once but now is used generally and imprecisely. Special education in reference to those whose learning is impeded by some mental or physical handicap is from 1972.

Special pleading. (a) The allegation of special or new matter, as distinguished from a direct denial of matter previously alleged on the other side. ... (c) In popular use, the specious but unsound or unfair argumentation of one whose aim is victory rather than truth. [Century Dictionary]

word-forming element used to make verbs, Middle English -isen, from Old French -iser/-izer, from Late Latin -izare, from Greek -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached.

The variation of -ize and -ise began in Old French and Middle English, perhaps aided by a few words (such as surprise, see below) where the ending is French or Latin, not Greek. With the classical revival, English partially reverted to the correct Greek -z- spelling from late 16c. But the 1694 edition of the authoritative French Academy dictionary standardized the spellings as -s-, which influenced English.

In Britain, despite the opposition to it (at least formerly) of OED, Encyclopaedia Britannica, the Times of London, and Fowler, -ise remains dominant. Fowler thinks this is to avoid the difficulty of remembering the short list of common words not from Greek which must be spelled with an -s- (such as advertise, devise, surprise). American English has always favored -ize. The spelling variation involves about 200 English verbs.

1831, "act of becoming specialized," noun of action from specialize. Biological sense from 1862. In science and scientific education, "a direction of time and energies in one particular channel to the exclusion of others," by 1880.

If you peruse the people in the news

The people that the magazines refer to

You'll find that they are naturally soignée

The special ones that all of us defer to

They've each a trait that seems to state first raters

That separates them from the small potaters

["Specialization," lyrics by Sammy Cahn]