a small usually single-celled asexual reproductive body produced by many nonflowering plants and fungi and some bacteria and protozoans and that are capable of developing into a new individual without sexual fusion; "a sexual spore is formed after the fusion of gametes"
march aggressively into another's territory by military force for the purposes of conquest and occupation; "Hitler invaded Poland on September 1, 1939"
penetrate or assault, in a harmful or injurious way; "The cancer had invaded her lungs"
occupy in large numbers or live on a host; "the Kudzu plant infests much of the South and is spreading to the North"
(microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered plants
move from one country or region to another and settle there; "Many Germans migrated to South America in the mid-19th century"; "This tribe transmigrated many times over the centuries"
move periodically or seasonally; "birds migrate in the Winter"; "The workers migrate to where the crops need harvesting"