"the study of rocks and their mineralogical composition," 1811 (erroneously as petralogy), from petro- (1) "rock" + -logy. Related: Petrological; petrologist.

1590s, "the science of time," from French chronologie or directly from Modern Latin chronologia; see chrono- + -logy. Related: Chronologer (1570s). Meaning "particular statement of the supposed order of certain past events" is from 1610s.

"the science of the sounds uttered by the human voice or used in a particular language, phonetics; that part of grammar which treats of pronunciation; the system of sounds and of their combinations in a language," 1799, from phono- + -logy. Related: Phonologist; phonologic.

"the study of voting and elections," 1952, from Greek psēphizein "to vote" (properly "to vote with pebbles," from psēphos "pebble;" see psephocracy) + -logy.

"register of deaths, obituary notices," 1705, from necro- "death" + -logy. Originally of those connected with a certain institution; by 1854 in reference to persons who died within a certain time. Related: Necrologic; necrological; necrologist.

"science which treats of the properties of minerals," 1680s, a hybrid from mineral (n.) + -logy or else from French minéralogie (1640s). Related: Mineralogist; mineralogical.