The most common and most likely answer to this crossword clue is the 7 letter word INVERSE
I've seen this crossword clue in The Daily Telegraph
I
N
V
E
R
S
E
More clues leading to the result INVERSE
- Opposite of how most poets write
- Contrary writing style of McGonagall?
- . Contrary way poets work
- Opposite of poetic
- The opposite of “poetically”?
- One with shattered nerves? Just the opposite
- How poetry may be written upside down
- Like something a poet’s written or the opposite
- Not prosaic — the opposite
- Fashionable to have very limited language? The opposite
Buddy explains!

The straight part
We know that "The opposite" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the opposite = inverse.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does INVERSE mean?
INVERSE noun- An inverted state: a state in which something has been turned (properly) upside down or inside out or backwards.
- The result of an inversion, particularly:
- A second element which negates a first; in a binary operation, the element for which the binary operation—when applied to both it and an initially given element—yields the operation's identity element, specifically:
- A morphism which is both a left inverse and a right inverse.
- The winning of the coup in a game of rouge et noir by a card of a color different from that first dealt; the area of the table reserved for bets upon such an outcome.
- (Kiowa-Tanoan) A grammatical number marking that indicates the opposite grammatical number (or numbers) of the default number specification of noun class.
- To compute the bearing and distance between two points.
- Opposite in effect, nature or order.
- Reverse, opposite in order.
- Inverted; having a position or mode of attachment the reverse of that which is usual.
- Having the properties of an inverse; said with reference to any two operations, which, when both are performed in succession upon any quantity, reproduce that quantity.
- That has the property of being an inverse (the result of a circle inversion of a given point or geometrical figure); that is constructed by circle inversion.
- (of a category) Whose every element has an inverse (morphism which is both a left inverse and a right inverse).