sprinkler head

noun

: the outlet of a sprinkler system that is usually a valve held closed by a strut having separable parts joined with solder of a predetermined melting point (such as 160°F) that fuses when exposed to fire temperatures and allows the head to open or by a quartz bulb containing a liquid that expands when heated and bursts the bulb

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

• More than 250,000 words that aren't in our free dictionary
• Expanded definitions, etymologies, and usage notes
• Advanced search features
• Ad free!