Answer:
Just use them. They are all adjectives!
新 SHIN, atara(shii), arata, nii - new
軽 KEI, karu(i), karo(yaka) - light
厳 GEN, GON, kibi(shii), ogoso(ka) - severe, strict, rigorous, solemn
久 KYUU, KU, hisa(shii) - long (time)
頼 RAI, tano(mu), tano(moshii), tayo(ru) - request, entrust, depend on, trustworthy