My comments in italics:
Guagua = n: Bus or Car, a form of transit.
I would have thought this was an omno-whatsit, you know, when the word derives from the sound associated the object, in this case a horn. Interesting that it is also the Quechua word for baby, probably for a similar reason.
Batata = n : Sweet Potato.
I always thought this was Arabic but as potatoes came from this side of the globe it is also likely that the name originated here/ Whatever the origin, this is the derivation of the English word for potato.
Many of the other words have not just filtered into Dominican Spanish, they are internationally recognised words in Spanish everywhere, and are well-known in English and other languages for that matter.
Barbacoa = n : A Stand, a four legged stand, made of sticks, used in the cooking process of roasting meat.
Origin of the English barbecue.
Canoa = n : Small Boat.
Canoe.
Hamaca = n : Hanging Bed.
Hammock.
Iguana = n : Large Green Lizard.
Same in English.
Manati = n : Sea Cow.
Also known as Manatee in English.
Sabana = n : Big Valle or Large Plain.
English Savannah.
Tabacu = n : Tabacco.
Tobacco.
The rest are definitely Dominican Spanish words, although some are well-known in other parts of the Spanish speaking greater Caribbean, like jaiba (Colombia),
jibaro (PR) and arepa (Venezuela and Colombia).
Aji for pepper is used as further afield as Ecuador, and tiburon is the standard Spanish word for shark.
This is fascinating. I've seen such lists at the Museo del hombre (sic) Dominicano and the Centro Leon, together with a list of African and archaic Spanish words in common use in the DR.