ageless, arrowlike, articulated, assiduous, catenated, ceaseless, chattering, coeternal, concatenated, connected, consecutive, consistent, constant, continual, continued, continuing, continuous, cyclical, dateless, dead straight, diligent, direct, dogged, endless, enduring, eternal, eterne, even, ever-being, ever-durable, ever-during, everlasting, everliving, faithful, featureless, flat, gapless, horizontal, immediate, immemorial, immutable, in a line, inalterable, incessant, indefatigable, indestructible, indomitable, industrious, infinite, insistent, interminable, invincible, irreversible, joined, jointless, lasting, level, lineal, linear, linked, loyal, machine gun, monotonous, never-ceasing, never-ending, never-tiring, nonstop, nonterminating, nonterminous, obstinate, olamic, one-way, orderly, oscillating, patient, patient as Job, perdurable, perennial, periodic, permanent, perpetual, perseverant, persevering, persistent, persisting, pertinacious, plodding, plugging, preoccupied, pulsating, rapid, rapt, rectilineal, rectilinear, recurrent, regular, relentless, repeated, repetitive, resolute, right, round-the-clock, ruler-straight, running, seamless, sedulous, sempiternal, sequent, sequential, serial, serried, single-minded, sleepless, slogging, smooth, stable, staccato, steadfast, steady, straight-cut, straight-front, straight-side, straight, straightaway, straightforward, straightway, streamlined, stubborn, stuttering, sustained, tenacious, through, tight, timeless, tireless, true, twenty-four-hour, unabating, unbending, unbent, unbowed, unbroken, unceasing, unchanging, unconquerable, uncurved, undaunted, undeflected, undeviating, undifferentiated, undiscouraged, undistorted, undrooping, unending, unfailing, unfaltering, unflagging, unflinching, unidirectional, uniform, unintermitted, unintermittent, unintermitting, unnodding, unrelaxing, unrelenting, unrelieved, unremitting, unsleeping, unstopped, unswerving, untiring, unturned, unvarying, unwavering, unwearied, unwearying, unwinking, upright, utterly attentive, vertical, vibrating, weariless, without end