lax C2+

/læks/ not strict or careful enough; slack

relaxable C2+

/rɪˈlæksəbəl/ capable of being relaxed, loosened, or eased

relaxative C2+

/rɪˈlæksətɪv/ tending to relax or loosen; something that produces relaxation

unrelaxed C2+

/ˌʌnrɪˈlækst/ tense; not at ease