pessimize
To take a pessimistic view of; to speak of in a negative or pessimistic way.
transitive
Mr. [Benjamin] Disraeli's Church appointments have been received with general satisfaction. There are two relations of the matter; the one as regards the prudence and astuteness of the dispenser of good things, and the other as relates to the general good and efficiency of the Church itself. It is equally possible to optimize and pessimize either aspect.
To think like a pessimist; to believe the worst.
intransitive
The pessimising and desponding tone of the Tory Foreign Minister's correspondence, in the early part of 1859, can hardly be read without a shudder.
To become pessimal or the worst.
intransitive
Without an effort to integrate the various design disciplines, for instance, individual subsystems (such as the HVAC system) may be optimized, but the system as a whole may be "pessimized."
Where it comes from
From Latin pessimus (“worst”) + -ize, modelled after optimize. Pessimus is derived from Proto-Indo-European *ped-tm̥mó-s, from *ped- (“to step, walk; to fall, stumble”) + *-tm̥mó-s (superlative suffix).
Adapted from the Wiktionary entry pessimize (CC BY-SA 4.0).