want > lack squire > attendant; knight's attendant late > recently

5 For whom he wondrous pensive grew in mind,

pensive > anxious

6 For doubt of danger which might him betide;

doubt > fear betide > befall

7 For him he loved above all mankind, 8 Having him true and faithful ever tried,

tried > proved

9 And bold, as ever squire that waited by knight's side.

waited > attended; kept watch

305.13