Topic adjectives are listed in this post. Each word below can often be found in front of the noun topic in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing TOPIC.
absorbing, academic, acceptable, active, actual, advanced, agreeable, appropriate, assigned, basic, best, better, big, broad, broader, burning, button, central, certain, challenging, chief, chosen, common, complex, complicated, conceivable, congenial, constant, contentious, controversial, conversational
critical, crucial, current, daily, dangerous, debated, delicate, different, difficult, disagreeable, distinct, dominant, easy, emotional, engrossing, entire, essential, exact, exciting, explicit, extensive, familiar, fascinating, fashionable, favorite, favourite, fertile, final, first, fit, focused
following, former, frequent, fresh, fruitful, fundamental, further, general, good, grand, great, heated, historical, hot, hottest, huge, imaginable, immediate, important, inexhaustible, initial, interesting, intriguing, key, kindred, large, larger, last, latter, leading, legal
legitimate, literary, lively, main, major, momentous, more, narrow, natural, neglected, neutral, new, next, obscure, obvious, off, old, only, ordinary, original, other, overall, own, painful, particular, perennial, personal, philosophical, pleasant, political, popular
possible, present, prevailing, previous, primary, prime, principal, prominent, proper, public, real, recent, recurrent, recurring, regular, related, relevant, religious, researched, rich, right, safe, safer, same, scientific, second, selected, sensitive, separate, serious, significant
similar, single, social, sole, special, specialized, specific, standard, standing, such, suitable, taboo, technical, theological, third, timely, uncomfortable, unfamiliar, universal, unpleasant, unrelated, unusual, useful, usual, vast, very, vital, whole, worthy
Hope this word list had the adjective used with topic you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.