The modern meaning "shabby, no longer fresh or new" is attested by 1739, probably in reference to the appearance of a flowering plant that has run to seed; compare figurative expressions go to seed (by 1817), etc., originally of plants, "to cease flowering as seeds develop." Related: Seediness.
1732, "fall together, fall into an irregular mass through loss of support or rigidity," from Latin collapsus, past participle of collabi "fall together," from assimilated form of com "with, together" (see com-) + labi "to fall, slip" (see lapse (n.)).
Figurative sense of "come to nothing, fail" is from 1801. Transitive sense "cause to collapse" is from 1883. The adjective collapsed is attested from c. 1600, originally of groups of persons, "fallen from a spiritual or religious state," perhaps from co- + lapsed. Related: Collapsing.
c. 1600, "exact correspondence in substance or nature," from French coincidence, from coincider, from Medieval Latin coincidere, literally "to fall upon together," from assimilated form of Latin com "with, together" (see com-) + incidere "to fall upon" (from in- "upon" + combining form of cadere "to fall," from PIE root *kad- "to fall").
From 1640s as "occurrence or existence during the same time." Meaning "a concurrence of events with no apparent connection, accidental or incidental agreement" is from 1680s, perhaps first in writings of Sir Thomas Browne.
"to fall or fall into with a sound like 'plop,' " 1821, imitative of the sound of a smooth object dropping into water. Related: Plopped; plopping. Thackary (mid-19c.) used plap (v.). As a noun from 1833.