How to say "full-blown" in Japanese

• 本格的ほんかくてきCommon
  na-adjectiveThe common word for 'full-blown' meaning full-scale, all-out, or full-fledged: something under way at full scale or intensity, no longer tentative — a conflict, investigation, or pursuit that has become the real thing.
  本格的ほんかくてきな休暇きゅうかは３年ねんぶりだ。↗

  It's three years since I had a real vacation.
• 本式ほんしき
  no-adjective, na-adjectiveReally means 'proper', 'serious', or 'in earnest'; its 'full-blown' use is chiefly seasonal, as in 'full-blown winter'. Less common than 本格的, it is seldom the word you want for other senses of 'full-blown'.

For 'full-blown' meaning full-scale, all-out, or full-fledged, use the common 本格的; the less common 本式 really means 'proper, in earnest' and fits 'full-blown' chiefly of the weather, as in full-blown winter.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 本格的ほんかくてきfull-scale
• 本式ほんしきin earnest