The quality or state of being grandmotherly; the characteristic warmth, affection, and caring nature associated with grandmothers.
From grandmotherly (grandmother + -ly adjective) plus -ness, a suffix creating nouns of quality or state. This compound shows how English builds abstract qualities from concrete relationships.
There's something linguistically interesting here: we use -liness to describe nurturing qualities (like kindliness from kind), suggesting that warmth and caring are seen as essential feminine character traits across many languages!
Complete word intelligence in one call. Free tier — 50 lookups/day.