ālambana (Sanskrit, foundation, basis). A cognitive object; anything functioning as the objective support or basis of perception, whether in normal states of consciousness (vijñāna) or during meditation. There are six such objects, corresponding to the traditional Indian classification of the six senses, namely the objects of sight, sound, smell, taste, touch, and ideation. The first five are classified as material in form, while the sixth may be physical or mental, as well as past, present, or future. See also āyatana.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)

ālambana : [nt.] 1. a sense-object; 2. hanging down from; 3. support.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Ālambana (adj. -- nt.) [fr. ā + lamb, cp. ālamba] (adj.) hanging down from, hanging up J iii.396; iv.457; SnA 214. -- (nt.) support, balustrade (or screen?) Vin ii.117, 152 (˚bāha) Miln 126.

Pali-English Dictionary, TW Rhys Davids, William Stede,

ālambana: Cognitive object, a dharmacapable of generating a cognition of itself.

Sarvastivada Abhidharma, Sanskrit-English Glossary, by Bhikkhu KL Dhammajoti