Dissemble means to hide your true feelings or intentions, while disassemble means to take a physical object apart, piece by piece. If someone is lying about how they feel, they dissemble; if someone is taking an engine apart, they disassemble it.
The core difference
Dissemble is about concealing the truth, while disassemble is about taking something apart physically or digitally.
- dissemble — to disguise or conceal one's true feelings, opinions, or intentions: He smiled and dissembled, giving no hint of his anger.
- disassemble — to take something apart, especially a machine: He disassembled the engine to clean each part.
How to tell them apart
The spellings differ by only one letter, which is where the confusion comes from, but the words have separate histories. Dissemble comes down through Old French from Latin dissimulo, tied to the idea of putting on a false semblance. Disassemble is simply dis- attached to assemble, describing the reverse of putting something together.
A quick memory hook: disassemble contains the word assemble, so it always involves parts and a physical or digital structure. Dissemble has no such clue, so if the sentence is about hiding feelings rather than taking something apart, that is the one you want.
