noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   Movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy. uncountable
2. 2
   transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient; requires an expenditure of energy wordnet
3. 3
   Walking and cycling as means of travel. uncountable

Synonyms

All synonyms

bicycling

Antonyms

All antonyms

osmosisoxygen diffusion into tissuespassive