Luigification
Luigification (also known as Semi-Cloning or Partial Cloning) is an unofficial term used in the Super Smash Bros. fan community. It describes a character whose moveset is loosely based on that of an original character's, but is different enough not to be considered a "clone". The term originates from Luigi, whose entire special moveset in each installment of the "Smash" series, were variations of Mario's (except for his side special in Super Smash Bros. Melee), but had unique normal moves which differentiated him from being classified as a clone. Because no character other than Luigi fell into this category previously, these terms are primarily used in reference to characters in exclusively in Super Smash Bros. Brawl. Because this an unofficial term, its use is open to interpretation and is often used broadly. Unlike the official "clone" term used for certain Melee characters, there is no established criteria that determines "Luigification", only the personal opinion of the individual using of the term.
Possible Examples of "Luigification"
Luigi and Mario
Remaining Clone aspects: Low
Obviously, their relationship is what coined the term "Luigification". In the original Super Smash Bros., Luigi could easily be considered a clone of Mario, lest for one different normal move. However, in Super Smash Bros. Melee, with the addition of the Smash B move, Luigi and Mario were "Luigified" with entirely different standard moves. In Super Smash Bros. Brawl, Luigi and Mario were "Luigified" even further with entirely different Final Smashes and Down Special Moves.
Lucas and Ness
Remaining Clone aspects: Less than half
Lucas and Ness's basic special movesets are similar but have different properties. They are "Luigified" by their entirely separate normal movesets.
Falco and Fox
Remaining Clone aspects: Slightly below Half
Falco was a direct clone of Fox in Super Smash Bros. Melee. Falco's Super Smash Bros. Brawl design underwent several "Luigifying" changes that now largely differentiate his normal moveset. While, Falco's special moveset still remains a cloned version of Fox's, it has been further altered with more differences-- Falco now kicks his Reflector in front of him then retracts it back, instead of generating it around his body like Fox. His Up Special, however, seems to have the same initial "fireburst" hitbox while charging, however.
Wolf and Fox
Remaining Clone aspects: Less than half
Much like Falco, Wolf's moveset is loosely based off Fox's in that they share the same basic special moveset, though like most "cloned" moves, their exact functions are still different. Unlike Falco, Wolf and Fox have completely separate normal moves.
Ganondorf and Captain Falcon
Remaining Clone aspects: Below Half
While Ganondorf's Melee incarnation was a direct clone of Captain Falcon, his Brawl design has undergone several changes that separates the pair. He now has a different Standard attack animation; longer range, a different animation for Warlock Punch, new side Special: Flame Choke, and altered Up Special has uppercut at end of animation. They also have completely unrelated Final Smashes.
Ike and Marth
Remaining Clone aspects: Very low
While loosely based off Marth, Ike's high level of Luigification greatly distinguishes himself from Marth. Ike's Eruption move is a variation the Melee version of Marth's Shield Breaker/Roy's Flare Blade, while the Brawl version of Marth's Shield Breaker has been reworked further distinguishing it from Ike's Eruption. Ike and Marth's up specials are executed quite differently. The only truly identical move the two share are their down special, Counter. The two have entirely different Final Smashes.
Toon Link and Link
Remaining Clone aspects: Very high
The amount of Toon Link and Link's "Luigification" is minor at best. Both share variations of all their special moves and the vast majority of their normal moves. Many people may even consider Toon Link the only "true" clone of Brawl; however, because he and Link do not share all the same normal moves, some argue that they should not be considered such. For example, unlike Toon Link, Link has a Sex Kick.