Grand style is a term used for poetry that speaks with high seriousness, dignity, and elevated language. It usually suggests a noble or stately manner rather than everyday speech, often marked by large-scale subject matter, formal rhythm, and a confident, memorable voice. Matthew Arnold used the phrase to praise poets such as Homer, Dante, Milton, and Pindar.
It does not simply mean "fancy" or "ornate" writing; the grand style depends on force, clarity, and moral or emotional weight.
Example
Across the thundered valley of the night
we lift our banners toward the gathering stars;
our mortal hands are small, yet still we stand
and call the dark to witness who we are.