Spears and poles

Basque langa 'enclosure, rustical door; bar, catch (on a door or window)'¹ is related to Occitan/Catalan tanca id.², with a sound shift *t- > l- in Proto-Basque.

This is an Italoid substrate loanword whose etymology is IE *tengh-s- 'pole' > Latin tēmō 'steering-wheel; spear (of a cart)' and Old English þīsl 'wagon-pole, shaft'³. This IE root is a -n- infixed variant of *(s)teg- 'pole, post' (English stake), which in turn is related to PNC *dwɨq’(w)V: 'log, stump'.

This Vasco-Caucasian root is found as a Vasconic loanword in Spanish taco, Catalan tac 'block of wood, wedge; wooden stick', French taquet (diminutive form) 'block of wood, wedge', as well as in Basque haga 'pole, stake'⁴. The Tyrrhenian variant is found in Spanish tocón (augmentative form), Portuguese tôco 'stump' and also in Catalan soca, French souche 'stump', Old French choque 'log' and Spanish zoquete (diminutive form) 'block of wood; dumb, stupid'⁵, with assibilation of the initial dental.
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¹ Mitxelena derives it from Romance *planka 'plank, board'.
² Coromines proposes a derivation from a hypothetical Sorotaptic verb *tankō- 'to close'.

³ See Mallory & Adams (2006), p. 249.
⁴ There's also non-standard Basque tako 'circular piece of wood' and taket 'stake, wedge; dump, stupid'.

⁵ Coromines considered this word to be an arabism. What a zoquete!