Most Americans say, He will live! After all, the thumbs-up sign is a positive thing. It's how we encourage our friends and silently show approval. But to the ancient Romans, a thumbs up mimicked the upward thrust of a sword through the heart. It meant, kill. A thumbs-down meant put your sword down. So where did this confusion about thumbs come from?
Freebase(0.00 / 0 votes)Rate this definition: Transfection. Transfection is the process of deliberately introducing nucleic acids into cells. The term is used notably for non-viral methods in eukaryotic cells.
metaphor noun [C/U]. âº literature an âexpression that âdescribes a âperson or âobject by referring to something that is âconsidered to âpossess âsimilar characteristics: [C] A âheart of âstone is a metaphor. metaphorical adjective us /ËmetÌ¬Â·ÉËfÉrÂ·ÉªÂ·kÉl, -ËfÉr-/ âº metaphorical âexpressions.