Christmas tree

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

• noun An evergreen or artificial tree decorated, as with lights and ornaments, during the Christmas season.
• noun A device that consists of pipes and valves and caps a producing natural gas or oil well in order to control its flow.

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

• noun A conifer used during the Christmas holiday season, typically decorated with lights and ornaments and often a star or angel at its tip.
• noun racing A pole with lights, similar to a traffic signal, used for signalling the start of an automobile race.
• noun The collection of valves sometimes found at the top of a working oil well.
• noun bodybuilding A pattern of muscles visible in the lower back, shaped to look like a conifer.

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

• noun tall timber tree of central and southern Europe having a regular crown and grey bark
• noun medium to tall fir of western North America having a conic crown and branches in tiers; leaves smell of orange when crushed
• noun Australian tree or shrub with red flowers; often used in Christmas decoration
• noun an ornamented evergreen used as a Christmas decoration
• noun a terrestrial evergreen shrub or small tree of western Australia having brilliant yellow-orange flowers; parasitic on roots of grasses