clay meaning
EN
[kleɪ] [-eɪ] 
US WClay
- Clay is a fine-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Clays are plastic due to their water content and become hard, brittle and non–plastic upon drying or firing.
- Clays are distinguished from other fine-grained soils by differences in size and mineralogy. Silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays.
EN Clay 
- NounPLclays
- A mineral substance made up of small crystals of silica and alumina, that is ductile when moist; the material of pre-fired ceramics.
- An earth material with ductile qualities.
- (tennis) A tennis court surface.
- The French Open is played on clay.
- (biblical) The material of the human body.
- (geology) A particle less than 3.9 microns in diameter, following the Wentworth scale.
- (firearms, informal) A clay pigeon.
- A mineral substance made up of small crystals of silica and alumina, that is ductile when moist; the material of pre-fired ceramics.
- VerbSGclaysPRclayingPT, PPclayed
- (transitive) To add clay to, to spread clay onto.
- (transitive, of sugar) To purify using clay.
- (transitive) To add clay to, to spread clay onto.
- More Examples
- Used in the Middle of Sentence
- Some old, underfired clay pantiles might be damaged by button mosses rooting in cracks and fissures. But most post-war tiles are hard enough to withstand a bit of moss growth.
- I slowly smashed the modeling clay flat with the palm of my hand.
- A properly made, fully sintered and fully annealed metal clay piece should be able to stand up to any traditional metalsmithing technique.
- Used in the Ending of Sentence
- Learning to make a pinch pot is a great way to gain some experience with manipulating soft clay.
- Used in the Middle of Sentence
Definition of clay in English Dictionary
- Part-of-Speech Hierarchy
- Nouns
- Countable nouns
- Singularia tantum
- Uncountable nouns
- Uncountable nouns
- Countable nouns
- Verbs
- Transitive verbs
- Transitive verbs
- Nouns
Source: Wiktionary
Grammatically, this word "clay" is a noun, more specifically, a countable noun and a singularia tantum. It's also a verb, more specifically, a transitive verb.