Before Newton many phycisists try to understand nature and the rotations of planets. But Newton founded his laws of gravity. But was he the first who used the word gravity or when was it first used? And comes the word gravity from the word 'grievous'? Or was Aristotle or Galilei before him using that word? Of course they spoke another language but perhaps the already used βαρύτητα or gravità?
Let us then apply the term ‘heavy’ (βάρος) to that which naturally moves towards the centre, and ‘light’ to that which moves naturally away from the centre. (De Caelo, 269b)
Isaac Newton uses gravity in his Philosophiae Naturalis Principia Mathematica (1687, 3rd Latin ed, 1726):
A centripetal force is that by which bodies are drawn or impelled, or any way tend, towards a point as to a centre.
Of this sort is gravity [gravitas], by which bodies tend to the centre of the earth.
Thus, Newton did not invent the word, but was the author of a crucial "shift of meaning": previously "gravity" denoted a quality, then a force.
For sure, Newton "invented" the force of gravity [vi gravitatis].
Note. Galileo Galilei in his Dialogue (in Italian) uses: gravità and leggerezza for heaviness and lightness, respectively.