Synonyms for On-the-spot:

• adj.

  •extemporaneous (adjective)
  • fake,
  • ad-lib.
  •extemporaneous/extemporary (adjective)
  • ad hoc,
  • casual,
  • extempore,
  • off the cuff,
  • made-up,
  • spontaneous,
  • makeshift,
  • spur-of-the-moment,
  • informal,
  • offhand,
  • unprepared,
  • unplanned,
  • winging it,
  • impromptu,
  • expedient,
  • automatic,
  • unstudied,
  • snap,
  • free,
  • unpremeditated.
  •present (adjective)
  • show up,
  • made the scene,
  • ready,
  • near,
  • accounted for,
  • at hand,
  • there,
  • in attendance,
  • there with bells on,
  • in view.
  •snappy (adjective)
  • sudden,
  • expeditious,
  • rapid,
  • breakneck,
  • fleet,
  • speedy,
  • hasty.
  •spur-of-the-moment (adjective)
  • spur of the moment.

• adv.

  •here (adverb)
  • hither,
  • attending,
  • available.

• n.

  •
  • fast,
  • straight,
  • headlong,
  • right now,
  • at once.

• Other synonyms:

  •
  • forthwith,
  • lightning,
  • fast track,
  • attendance,
  • abrupt,
  • straightaway,
  • bang,
  • impulsive,
  • precipitous,
  • promptly,
  • impetuous,
  • Posthaste,
  • poof,
  • prompt,
  • already,
  • now,
  • summary,
  • summarily,
  • swift,
  • suddenly,
  • straight away,
  • short,
  • availability,
  • PDQ,
  • instantly,
  • fast-paced,
  • attendee,
  • wham-bam,
  • directly.
  •
  • flat,
  • flash,
  • presence,
  • slap,
  • violently,
  • presto,
  • bodily,
  • quick,
  • immediate,
  • rude,
  • cold.
  •
  • attendant,
  • right.
  •
  • kick around.
  •at once
  • immediately.

Paraphrases for On-the-spot:

• Equivalence

  • Adjective
    on-site.
  • Noun, singular or mass
    on-site.

• Independent

  • Adjective
    on-premise, field-level, immediate, on-the-job, in-place, in-field, on-farm, non-local.
  • Adverb
    onsite.

• Other Related

  • Adjective
    on-the-ground, on-scene, onsite, local.
  • Noun, singular or mass
    onsite.

Antonyms for On-the-spot:

• adj.

  • extemporaneous
    deliberate, premeditated.
  • extemporaneous/extemporary
    prepared, written, read, Rehearsed, planned.
  • instant
    late, future, old, unimportant, old-fashioned, past, delayed, slow, later, tardy, eventual.
  • present
    away, previous, far, absent, former, distant.
  • snappy
    nice, unfashionable, pleasant, happy, sluggish, outdated.

• adv.

  • here
    there.
  • Other antonyms:
    off-site.