dried out: shrivelled and without moisture, whether a limb that has withered, wood that is dead, or ground as opposed to sea
One picture stands behind every use of this word: the moisture is gone. Something that ought to be supple and full of sap has dried out, shrunk, and stiffened. Greek speakers applied it to firewood, to ground, and to a human limb, and the New Testament uses it all three ways without the sense shifting.
Its most frequent use is a person's hand. Matthew 12:10, Mark 3:3, Luke 6:6 and Luke 6:8 all describe the man in the synagogue whose hand had dried up and would not work, and John 5:3 stretches the word to a whole group of people lying by the pool, not just to one limb. English Bibles usually say "withered" here, and sometimes "paralyzed", so a reader rarely notices that this is the same word Luke later uses for firewood.
The other two uses run away from the body. In Luke 23:31 Jesus sets dry wood against green, living wood (ὑγρός), a proverb about what happens when fire reaches what is already fit to burn. In Matthew 23:15 and Hebrews 11:29 the word describes ground: the solid land opposite the sea, and the seabed Israel walked across. The related verb (ξηραίνω) names the drying itself, while this word names the state that drying leaves behind.