1d. Great reveal is put off (11)
3d. Every succeeding royal contact (5)
13a. Consideration while tense (7)
17a. Philosopher attached to a military unit (7)
1d Superlative ( anagram of reveal is put )
3d Reach. ( every =each ) succeeding (after ) royal ( R )
13a Thought. While = though + (t)ense
17a Platoon. ( philosopher = Plato ) attached ( on )