Jotham = "Jehovah is perfect"
derivation: from (03068) and (08535)
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=03147&version=kjv

(03068)
Jehovah = "the existing One"
derivation: from (01961)
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=3068&version=kjv

(01961)
1] to be, become, come to pass, exist, happen, fall out
   1.a] (Qal)
       1.a.1] to happen, fall out, occur, take place, come about, come to pass
       1.a.2] to come about, come to pass
           1.a.2.a] to come into being, become
       1.a.3] to arise, appear, come 1a
       1.a.4] to become
           1.a.4.a] to become
           1.a.4.b] to become like
           1.a.4.c] to be instituted, be established
           1.a.4.d] to be
       1.a.5] to exist, be in existence
       1.a.6] to abide, remain, continue (with word of place or time)
       1.a.7] to stand, lie, be in, be at, be situated (with word of locality)
       1.a.8] to accompany, be with
   1.b] (Niphal)
       1.b.1] to occur, come to pass, be done, be brought about
       1.b.2] to be done, be finished, be gone
derivation: a primitive root [compare (01933)]
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=1961&version=kjv

(01933)]
1] Qal)
   1.a] to fall
   1.b] to be, become, exist, happen
derivation: a primitive root [compare (0183), (01961)]
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=1933&version=kjv

(0183)
1] desire, incline, covet, wait longingly, wish, sigh, want, be greedy, prefer
   1.a] (Piel) to desire, crave (food and drink)
   1.b] (Hithpael) to desire, long for, lust after (of bodily appetites)
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=183&version=kjv

(08535)
1] perfect, complete
   1.a] complete, perfect
       1.a.1] one who lacks nothing in physical strength, beauty, etc
   1.b] sound, wholesome
       1.b.1] an ordinary, quiet sort of person
   1.c] complete, morally innocent, having integrity
       1.c.1] one who is morally and ethically pure
derivation: from (08552)
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=8535&version=kjv

(08552)
1] to be complete, be finished, be at an end
   1.a] (Qal)
       1.a.1] to be finished, be completed 1a
   1.b] completely, wholly, entirely (as auxiliary with verb)
       1.b.1] to be finished, come to an end, cease
       1.b.2] to be complete (of number)
       1.b.3] to be consumed, be exhausted, be spent
       1.b.4] to be finished, be consumed, be destroyed
       1.b.5] to be complete, be sound, be unimpaired, be upright (ethically)
       1.b.6] to complete, finish
       1.b.7] to be completely crossed over
   1.c] (Niphal) to be consumed
   1.d] (Hiphil)
       1.d.1] to finish, complete, perfect
       1.d.2] to finish, cease doing, leave off doing
       1.d.3] to complete, sum up, make whole
       1.d.4] to destroy (uncleanness)
       1.d.5] to make sound
2] (Hithpael) to deal in integrity, act uprightly
http://bible.crosswalk.com/Lexicons/Hebrew/heb.cgi?number=8552&version=kjv

A link to each occurrence of this word in the homepage:
1] Jotham