Bug
Etymology
Engineers called mechanical faults "bugs" well before computers; Thomas Edison used the term in 1878 for defects in his inventions. The famous 1947 moth taped into a Harvard Mark II logbook by Grace Hopper’s team is often told as the origin, but it was a knowing joke precisely because the word was already standard — they noted it as the first actual bug found. The insect metaphor likely evokes something small that crept in unbidden.
noun · /BUG/
A flaw in software or hardware that makes it behave incorrectly.
What it names
The ordinary, expected imperfection in anything built — the gap between what code was meant to do and what it actually does.
Example
A single off-by-one bug caused the app to skip every hundredth transaction.
Related idea
A bug is an unintended flaw, unlike a glitch, which usually means a brief, often self-correcting malfunction — and unlike a deliberate design choice a company later shrugs off as "working as intended."
verb · /BUG/
To secretly install a hidden microphone or listening device somewhere in order to eavesdrop.
What it names
Covert surveillance in a single verb — the spy’s tool, distinct from both the insect and the coder’s flaw.
Example
Investigators discovered that the embassy conference room had been bugged.
Related idea
Covert eavesdropping in a single verb — a concealed ear planted in one room, targeted and physical, unlike the mass, remote data-harvesting of surveillance capitalism.
verb · /BUG/
To annoy, irritate, or persistently bother someone.
What it names
Low-grade, nagging irritation — something that keeps needling at the edge of your attention.
Example
It really bugs me when people leave the milk out.
Related idea
To pester is to bother with repeated demands; to bug is broader — anything that irritates, even a thought that won’t leave you alone, like an insect that won’t stop buzzing.
noun · /BUG/
A microbe that causes illness, or the minor illness it produces.
What it names
It is the casual word for a passing infection — a ‘stomach bug,’ ‘a bug going around’ — without naming the exact pathogen.
Example
Half the office is out with some kind of bug.
Related idea
A virus is one specific class of infectious agent; a ‘bug’ is the informal catch-all for whatever germ is making people sick. A disease vector is the organism that carries such a bug between hosts.