underly

From under +‎ -ly.

• IPA^(key): /ˈʌndə(ɹ)li/

underly (comparative more underly, superlative most underly)

1. (dialectal) Poor; inferior.

underly (comparative more underly, superlative most underly)

1. (rare, obsolete) At a lower level.
   • 1672, Nehemiah Grew, The anatomy of vegetables begun:

     The Seed-Branch […] is presently divided into two main Branches, and those two into other less; whereof some underly, others aloft, run along the Coat.

2. (chiefly colloquial) In an inferior or inadequate manner; insufficiently (chiefly in opposition to overly).
   • 2000, William C. Heffernan, John Kleinig, From Social Justice to Criminal Justice, page 109:

     In this case, we are not in a position—at least from the perspective of the rules themselves and the values that lie behind them—to say that they are overly or underly inclusive.

   • 2014, Jass Richards, Licence to Do That:

     Overly madeup and underly dressed young women were dancing in a cluster on the floor.

   • 2016 July 3, Victoria Coren Mitchell, The Observer:

     Better to struggle claustrophobically from the grasp of an overly adoring parent than to fall serially in love with emotionally cruel or distant partners, which is what everyone with underly adoring parents always does.

Back-formation from underlying.

• IPA^(key): /ˌʌndə(ɹ)ˈlaɪ/

underly (third-person singular simple present underlies, present participle underlying, simple past underlay, past participle underlain)

1. Nonstandard spelling of underlie.
   • 1967, R. D. Laing, The Politics of Experience and the Bird of Paradise:

     I asked him what principles he felt should underly the care provided during such a voyage.

• underlied