cassava vs manioc

cassava and manioc both are nouns.

Word	Noun	Adjective	Verb	Adverb
cassava	Yes	No	No	No
manioc	Yes	No	No	No

As nouns, manioc is a hyponym of cassava; that is, manioc is a word with a more specific, narrower meaning than cassava:

cassava: any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch
manioc: cassava with long tuberous edible roots and soft brittle stems; used especially to make cassiri (an intoxicating drink) and tapioca

As nouns, cassava and manioc are synonyms defined as:

cassava and manioc: cassava root eaten as a staple food after drying and leaching; source of tapioca

As nouns, cassava and manioc are synonyms defined as:

cassava and manioc: a starch made by leaching and drying the root of the cassava plant; the source of tapioca; a staple food in the tropics

Other synonyms of cassava include cassava starch, manioca.

cassava (noun)	manioc (noun)
any of several plants of the genus Manihot having fleshy roots yielding a nutritious starch	cassava with long tuberous edible roots and soft brittle stems; used especially to make cassiri (an intoxicating drink) and tapioca
cassava root eaten as a staple food after drying and leaching; source of tapioca	cassava root eaten as a staple food after drying and leaching; source of tapioca
a starch made by leaching and drying the root of the cassava plant; the source of tapioca; a staple food in the tropics	a starch made by leaching and drying the root of the cassava plant; the source of tapioca; a staple food in the tropics