Plural of cathode; the negatively charged electrode in an electrical device where electrons are released.
From Greek 'kathodos' meaning the way down, describing the electrode through which current flows downward. Contrasts with 'anode' (way up).
In a battery, the cathode is actually the positive terminal—but in a vacuum tube it's negative—this flip in definitions confuses even physics students because the terms were defined differently in different contexts.
Complete word intelligence in one call. Free tier — 50 lookups/day.