Number & MeasureGreek → English
Meromorphic
/ˌmɛrəˈmɔrfɪk/adjective
Of a complex function, differentiable everywhere in a region except at isolated points where it blows up.
The Greek roots
μέρος
méros
part
μορφή
morphḗ
form, shape
Literally: “partly of good form”
The story of the word
The partner of holomorphic, coined with it by Briot and Bouquet in the 1870s: whole form for the well-behaved case, part form for the one with poles. The tangent function is the textbook example, perfectly smooth except at the points where the cosine underneath it vanishes. μέρος also stands behind polymer, many parts, and isomer, equal parts.
- How it travelled
- Ancient Greek → French mathematical coinage → English
- First recorded
- 19th century
Same family
holomorphicpolymerisomermorphology
In a sentence
The zeta function is meromorphic on the whole plane, with a single pole at one.
Ratios of holomorphic functions are meromorphic wherever the denominator has isolated zeros.