specialize

from The American Heritage® Dictionary of the English Language, 5th Edition.

• intransitive verb To pursue a special activity, occupation, or field of study.
• intransitive verb To provide something in particular or have something as a focus.
• intransitive verb Biology To become adapted to a specific function or environment; undergo specialization.
• intransitive verb To give a particular character or function to.
• intransitive verb Biology To adapt to a particular function or environment; cause to undergo specialization.
• intransitive verb Archaic To make specific mention of; specify.

from The Century Dictionary.

• To make individually or generically special or distinct; make specifically distinct; differentiate from other kinds in form, adaptation, or characteristics, as by a process of physical development; limit to a particular kind of development, action, or use. See specialization, 3.
• To mention specially or in detail; particularize; specify.
• To act in some special way; pursue a special course or direction; take a specific turn or bent.
• Also spelled specialise.

from the GNU version of the Collaborative International Dictionary of English.

• transitive verb To mention specially; to particularize.
• transitive verb To apply to some specialty or limited object; to assign to a specific use.
• transitive verb (Biol.) To supply with an organ or organs having a special function or functions.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• verb To mention specially; to particularize.
• verb To apply to some specialty or limited object; to assign to a specific use; as, specialized knowledge.
• verb biology To supply with an organ or organs having a special function or functions.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb suit to a special purpose
• verb become more focus on an area of activity or field of study
• verb be specific about
• verb devote oneself to a special area of work
• verb evolve so as to lead to a new species or develop in a way most suited to the environment