tissue
The word operates in two completely different worlds: the clinical and the domestic. In biological contexts, it evokes a structural image of interconnected cells forming a functional unit of a body, carrying a neutral, scientific tone. In everyday conversation, it almost exclusively refers to the disposable paper product. This usage is associated with hygiene, illness, or emotional distress, such as wiping away tears. It carries a connotation of fragility and temporary use, contrasting sharply with the permanent, structural nature of biological tissue.
Countable when referring to individual paper handkerchiefs you pull from a box. Uncountable when referring to biological matter like heart or lung tissue.
Meanings
A soft, disposable piece of absorbent paper used for wiping the nose or face.
"Grab a tissue for your runny nose."
A group of similar cells that perform a specific function in a living organism.
"The muscle tissue in the leg was damaged."