ナイフ [knife] in Japanese.
Final Fantasy I
Stats: ATK +5, ACC +10
Equip: ?
Buy: 4 gil (Sell: ? gil)
Shop: Cornelia
Drop: Minotaur
Description: A small knife
Final Fantasy II

Stats: ATK +3, ACC +75%, EVA +2%
Equip: all
Obtain: ?
Description: A small knife
Final Fantasy III

Stats: ATK 8, ACC 85, weight 0
Use: FRE, ONK, WAR, RDM, THF, DRK, BRD, NIN
Obtain: initial equipment on Luneth, Arc, Refia and Ingus
Type: Dagger
Final Fantasy V
Stats: ATK +4
Equip: most jobs
Buy: - (sell: 75 gil)
Obtain: initial equipment
Other: can be used with Spellblade
Airborne Brigade

N+
Type: Dagger, Element: -, Growth: Fast, Cost: 5
Attack: 340 (lv1), ? (lv40), ? (lv50), ? (lv60), ? (lv70), 960 (lv80)
Defense: 390 (lv1), ? (lv40), ? (lv50), ? (lv60), ? (lv70), 1,100 (lv80)
Obtain: any chest that gives this rank
Other: pictured is FF11's knife
N
Type: Dagger, Element: -, Growth: Fast, Cost: 2
Attack: 160 (lv1), ? (lv20), ? (lv25), ? (lv30), ? (lv35), 450 (lv40)
Defense: 130 (lv1), ? (lv20), ? (lv25), ? (lv30), ? (lv35), 370 (lv40)
Obtain: any chest that gives this rank
Pictlogica

Stats (lv1): STR +18
Stats (lv5): STR +28
Buy: - (sell: ? gil)
Obtain: initial equipment on Thief, Cannoneer, Dancer and Juggler
Use: Mythril Knife
Type: Dagger, Rarity: ★, Element: -
Record Keeper

Knife (II)
Stats: ATK +4, ACC 83 (lv1), ? (lv3), ? (lv5), ATK +19, ACC 83 (lv10)
Max Level: lv3 (initial), lv5 (first evolving), lv10 (second evolving)
Type: Dagger, Rarity: ★
Category: Equipment