Messier

[mes-ee-ey; French me-syey] /ˈmɛs iˌeɪ; French mɛˈsyeɪ/

noun
1.
Charles
[sharl] /ʃarl/ (Show IPA), 1730–1817, French astronomer.
[mes-ee] /ˈmɛs i/
adjective, messier, messiest.
1.
characterized by a dirty, untidy, or disordered condition:
a messy room.
2.
causing a :
a messy recipe; messy work.
3.
embarrassing, difficult, or unpleasant:
a messy political situation.
4.
characterized by moral or psychological confusion.
/ˈmɛsɪ/
adjective messier, messiest
1.
dirty, confused, or untidy

in reference to a catalogue of about 100 nebulae, star clusters and galaxies begun in 1758 by French astronomer and comet-hunter Charles Messier (1730-1817), who at the time was looking for an expected return of Halley’s comet and deceived by fuzzy objects that looked like distant comets in his telescope but turned out to not be.

What caused me to undertake the catalog was the nebula I discovered above the southern horn of Taurus on September 12, 1758, whilst observing the comet of that year. This nebula had such a resemblance to a comet in its form and brightness that I endeavored to find others, so that astronomers would no more confuse these same nebulae with comets just beginning to appear. [Messier, 1800]

The first version of the catalogue was published 1771, and the fuller version in 1781.

adj.

1843, “untidy,” from mess (n.) + -y (2). Figurative use (“unethical”) by 1924. Related: Messily; messiness.

adjective