acellular
acellular: adj. Biol.
1 having no cells; not consisting of cells.
2 (esp. of protozoa) consisting of one cell only; unicellular.

accreditation
antidepressant
antidepressant: n. & adj. --n. any drug or agent that alleviates depression. --adj. alleviating depression.

accompaniment
accompaniment: n.
1 Mus. an instrumental or orchestral part supporting or partnering a solo instrument, voice, or group.
2 an accompanying thing; an appendage. [F accompagnement (as ACCOMPANY)]

aluminium
aluminium: n. (US aluminum) a silvery light and malleable metallic element resistant to tarnishing by air. °Symb.: Al. øaluminium bronze an alloy of copper and aluminium. [aluminium, alt. (after sodium etc.) f. aluminum, earlier alumium f. ALUM + -IUM]

allure
allure: v. & n. --v.tr. attract, charm, or fascinate. --n. attractiveness, personal charm, fascination. øøallurement n. [ME f. OF alurer attract (as AD-, luere LURE 1)]

abetter
abetter: n. (also abettor) one who abets.

abalone
abalone: n. any mollusc of the genus Haliotis, with a shallow ear-shaped shell having respiratory holes, and lined with mother-of-pearl, e.g. the ormer. [Amer. Sp. abul×n]

aquarium
aquarium: n. (pl. aquariums or aquaria) an artificial environment designed for keeping live aquatic plants and animals for study or exhibition, esp. a tank of water with transparent sides. [neut. of L aquarius of water (aqua) after vivarium]

aquarius
Aquarius: n.
1 a constellation, traditionally regarded as contained in the figure of a water-carrier.
2 a the eleventh sign of the zodiac (the Water-carrier). b a person born when the sun is in this sign. øøAquarian adj. & n. [ME f. L (as AQUARIUM)]

adagio
adagio: adv., adj., & n. Mus. --adv. & adj. in slow time. --n. (pl. -os) an adagio movement or passage. [It.]

acoustic
acoustic: adj. & n. --adj.
1 relating to sound or the sense of hearing.
2 (of a musical instrument, gramophone, or recording) not having electrical amplification (acoustic guitar).
3 (of building materials) used for soundproofing or modifying sound.
4 Mil. (of a mine) that can be exploded by sound waves transmitted under water. --n.
1 (usu. in pl.) the properties or qualities (esp. of a room or hall etc.) in transmitting sound (good acoustics; a poor acoustic).
2 (in pl.; usu. treated as sing.) the science of sound (acoustics is not widely taught). øacoustic coupler Computing a modem which converts digital signals into audible signals and vice versa, so that the former can be transmitted and received over telephone lines. øøacoustical adj. acoustically adv. [Gk akoustikos f. akouo hear]

alphabet
alphabet: n.
1 the set of letters used in writing a language (the Russian alphabet).
2 a set of symbols or signs representing letters. [LL alphabetum f. Gk alpha, beta, the first two letters of the alphabet]

alopecia
alopecia: n. Med. the absence (complete or partial) of hair from areas of the body where it normally grows; baldness. [L f. Gk alopekia fox-mange f. alopex fox]