Dictionary.com
definitions

pipet

[pahy-pet, pi-]

noun, verb (used with object), pi·pet·ted, pi·pet·ting.

pipette.

pipette

[pahy-pet, pi-]

noun

a slender graduated tube used in a laboratory for measuring and transferring quantities of liquids from one container to another.

verb (used with object), pi·pet·ted, pi·pet·ting.

to measure or transfer a quantity of a liquid with a pipette.

Origin of pipette

From French, dating back to 1830–40; see origin at pipe1, -ette
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for pipetting

pipette

noun

a calibrated glass tube drawn to a fine bore at one end, filled by sucking liquid into the bulb, and used to transfer or measure known volumes of liquid

verb

(tr) to transfer or measure out (a liquid) using a pipette

Word Origin for pipette

C19: via French: little pipe, from pipe pipe 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for pipetting

pipette

n.

also pipet, 1818, from French pipette, from Middle French pipette "tube," diminutive of Old French pipe, from Vulgar Latin *pipa (see pipe (n.1)).

Online Etymology Dictionary, © 2010 Douglas Harper
pipetting in Medicine

pipette

n.

A narrow, usually calibrated glass tube into which small amounts of liquid are suctioned for transfer or measurement.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
pipetting in Science

pipette

[pī-pĕt′]

A graduated narrow glass tube, often with an enlarged bulb, used for transferring measured volumes of liquids.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.