1. To join two or more things or pieces together by overlapping and binding them at the ends. A noun or pronoun can be used between "splice" and "together." In the old days, film editors had to splice together filmstrips by hand. The wall we're building is longer than the lumber they gave us, so we'll have to splice the planks together to reach the length we need.
2. To interweave the strands of multiple fibrous structures in order to join them as one. A noun or pronoun can be used between "splice" and "together." You can undo the end of a rope, then splice it together with itself You'll need to splice the wires together in order to get the machine working again.
3. To combine two or more different things in order to alter something or create something new. A noun or pronoun can be used between "splice" and "together." The movie shift in tone so dramatically halfway through that you'd be forgiven for thinking that it had been spliced together from two different films. The author's latest book is little more than a rehash of the last three, splicing together the most memorable moments of each into a single narrative.
4. To cause two or more genetic samples to undergo recombination; to mix together the genes of two or more disparate things. A noun or pronoun can be used between "splice" and "together." The mad scientist was arrested for trying to splice humans and dolphins together. We've spliced together these different strains of tomato in order to create a breed that can withstand both intense high and low temperatures.
splice something together
to connect things together, usually by twisting or tying a joint between the two. I spent over an hour splicing the two ends of the ropes together, and it didn't hold for even a minute. He carefully spliced together the two ropes.